<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>02-jQuery的两把利器</title>
    <script src="https://cdn.bootcdn.net/ajax/libs/jquery/2.2.4/jquery.min.js"></script>
</head>
<body>
    <script>
        
        /**
         * jQuery 函数
        */
        console.log('$:', $)        // ƒ (a,b){return new n.fn.init(a,b)}
        console.log('typeof $:', typeof $)      // function
        console.log('$ === jQuery:', $ === jQuery)      // true
        console.log('$ === window.$:', $ === window.$)      // true

        /**
         * jQuery 对象
        */
        console.log('$():', $())        // n.fn.init {}
        console.log('typeof $():', typeof $())      // "object", 这个对象就是 jQuery 对象
        console.log('$() instanceof Object:', $() instanceof Object)        // true

    </script>    
</body>
</html>